Install, upgrade, and downgrade

Install and upgrade

What is the use of the zebos.conf file available in a NetScaler release?

A NetScaler appliance uses Zebos as the routing suite. The zebos.conf file available in a NetScaler release is the configuration file for Zebos.

I want to change the SSH port (22) on the NetScaler appliance to some other port. Is it possible to change the SSH port on the appliance?

Yes. You can change the SSH port on the NetScaler appliance by editing the sshd_config file in the /nsconfig directory. If the file does not exist in the /nsconfig directory, copy it from the /etc directory.

In the sshd_config file, edit the entry for Port 22 to Port <Number>, where <Number> is the target port number. If you do not want to restart the appliance and make the changes effective, terminate the sshd process by using the kill command, and then restart the process.

The flash directory is missing from the NetScaler appliance. What procedure should I follow to mount the flash directory?

To mount the flash directory, do the following:

Start the NetScaler appliance in single-user mode.

When the appliance starts, the following message appears:

Hit [Enter] to boot immediately, or any other key for command prompt. Booting [kernel] in 10 seconds…” Hit space and you should see the following prompt:

Type ‘?’ for a list of commands, ‘help’ for more detailed help.

Enter the following command to start FreeBSD in single-user mode:

boot –s

After the appliance starts, the following message appears:

Enter full pathname of shell or RETURN for /bin/sh:

Press Enter to display the # prompt.

Run the following command to mount the flash directory:

mount /dev/ad0s1a /flash

Note: If the preceding command displays an error message about permissions, run the following command to check the disk for consistency:

fsck /dev/ad0s1a

Run the mount command again to mount the flash directory.

Restart the appliance.

From the shell prompt, run the following command to verify that the flash directory is mounted:

df -kh

I want to log on to the NetScaler appliance without entering the password. Is it possible to configure SSH on the appliance to allow that?

Yes. You can configure SSH on the NetScaler appliance to log on without a password. However, you must provide your user name. To configure SSH for logging in without a password, do the following:

Run the following command to generate the public and private keys:

\# ssh-keygen -t rsa

Run the following command to copy the id_rsa.pub file to the .ssh directory of the remote host that you want to log on to:

\# scp id_dsa.pub \<user>@\<remote_host>/.ssh/id_dsa.pub

Log on to the remote host.

Change to the .ssh directory.

Run the following commands to add the public key of the client to the known public keys:

Verify that the appliance starts cleanly and the serial console displays output after the appliance starts.

You need to reset BIOS when the serial console does not respond. This usually happens after you upgrade the appliance and the serial console is disabled. However, you can still access the appliance by using the telnet or SSH utility.

I need to reset the NetScaler appliance to the factory defaults. What procedure should I follow?

To reset the NetScaler appliance to the factory defaults, you need to reset two environments: the NetScaler application environment and the base FreeBSD environment.
To reset the NetScaler application environment of the appliance to the factory defaults, do the following:

Make a backup of the appliance’s /nsconfig/ns.conf.

Delete the /nsconfig/ns.conf file.

Restart the appliance.To reset the FreeBSD environment of the appliance to the factory defaults, do the following:

Install a fresh NetScaler code image on the appliance. This overwrites a number of FreeBSD-level configuration files with default values.

Delete any users and groups that are added to the appliance, that is, all except the default users.

Delete the /etc/resolv.conf file.

Delete the entries that you have added to the /etc/hosts file.

If the /etc/rc.netscaler file exists, delete it.

Open the /etc/nsperm_group_suser file and make sure that all IOCTL entries are comment entries.

Open the /etc/rc.conf file and make sure that the syslogd_enable=NO entry is not changed to syslogd_enable=YES.

Open the /etc/syslog.conf file and make sure that there are no additional entries in the file.

Delete the contents of the /var/nslog, /var/nstrace, and /var/crash files.

If the syslog process is enabled on the appliance and the appliance creates log files locally, delete the contents of the log files listed in the /etc/syslog.conf file. The files are created in the /var/log directory. For example, if syslog process writes system events to the /var/log/events file, and sslvpn access events to the /var/log/sslvpnevents file, delete these files.

The appliance displays a message similar to the “Jun 21 12:20:18 ns /flash/ns-10.0-47.15: [1/2]dc0: NIC hang condition #663: TX 10000/10000, RX 0, HF 0” message on the console. What is the meaning of this message?

The message consists of the following components (shown here as examples):

#663: Number of times this condition has occurred on the appliance.

TX 10000/10000: Number of packets that the appliance attempted to transmit, and number of packets transmitted. If both numbers are the same, as in this example, the NIC transmitted all the packets that the appliance attempted to transmit.

RX 0: Number of packets received. In this example, no packet was received.

HF0: Number of hardware issues reported by the NIC. In this example, the NIC did not report any hardware issue.

If the appliance does not receive any packets, it reports a hang condition, because on a network it is very unlikely not to receive any packets. However, if the appliance is plugged into quite interface, you can ignore this error message.

After I upgraded the NetScaler release on the appliance, the appliance still displays the earlier release/build. What could be the reason?

The appliance displays the software version number from the /flash/boot/loader.conf file. If the kernel entry for the current NetScaler release is missing from that file, the appliance displays the last NetScaler release version for which the entry was available.
To resolve this issue, do the following:

Verify that the kernel file exists in the /nsconfig directory.

Check the /flash/boot/loader.conf file for an entry for the kernel.

(You can expect the entry for the kernel of the release/build that you just installed to be missing from the file.)

Open the loader.conf file in a text editor, such as the vi editor, and update the kernel entry for the new release/build.

Save and close the file.

Repeat step 2 through step 4 for the /flash/boot/loader.conf.local file.

Update the release/build entry in the ns.conf file.

Restart the appliance.

Since I upgraded the NetScaler release on the appliance, the LCD display on the front panel of the appliance displays the out of service message or does not display anything. How can I resolve this issue?

Run the following command from the appliance’s shell prompt:

/netscaler/nslcd –k

I have upgraded the NetScaler release/build. However, after the upgrade process, the appliance fails to start. Can I downgrade the appliance’s software to the previous release/build?

Yes. You can start the appliance with the kernel.old kernel file. When you restart the appliance, press the F1 key as soon as the appliance console displays the Press F1 message. Type kernel.old and press Enter.

After upgrading the NetScaler release on the appliance, I accidently deleted the kernel file from the /flash directory. As a result, I am not able to start the appliance. Is there a method for starting the appliance in this situation?

Yes. You can start the appliance by using the kernel.GENERIC kernel file, as follows:

When you restart the appliance, press the F1 key as soon as the appliance console displays the Press F1 message.

Type kernel.GENERIC and press Enter.

Login as the root user.

Reinstall the NetScaler release.

Restart the appliance.

After upgrading the appliance software to NetScaler release 10.0, I am not able to log on to the appliance, and the following message is appears

login: nsroot
Password:
connect: No such file or directory
nsnet_connect: No such file or directory
Login incorrect

I tried to resolve this issue by using the password recovery procedure, but I was not successful. Have I done something incorrectly?

You cannot resolve this issue by using the password recovery procedure. NetScaler releases 8.0 and later use the new licensing system, based on the Imgrd daemon, which runs during the startup procedure. For this daemon to work properly, the host name of NetScaler appliance, which is set in the /nsconfig/rc.conf file, must be resolved by a name server to the NetScaler IP address. Alternately, you can create a hosts file in the /nsconfig directory and add the 127.0.0.1 <Host_Name> entry in file.

Additionally, make sure that you have copied the license files to the /nsconfig/license/ directory.

During an upgrade of a high availability pair, the following message appears repeatedly

<auth.err> ns sshd[5035]: error: Invalid username or password

What could be the reason?

This error message appears when the appliances involved in the high availability pairing have either a different NetScaler release or a different builds of the same release installed. The appliances can have different version installed if you have upgraded or downgraded one appliance but not the other.

I want to change the netmask of the NetScaler IP address on a NetScaler appliance. Can I do so without causing an outage?

Changing the netmask of the NetScaler IP might result in a short outage. Make sure that you change the netmask on the secondary appliance, and then break the high availability pairing. Check the functionality of the appliance. If everything works as expected, rebuild the high availability pairing.

To change the netmask on the appliance, run the configns command from the CLI prompt, and then choose the second option in the menu.

I have configured a High Availability pair of NetScaler appliances. After upgrading the software release from a beta release to a final release, I noticed that some of the appliance configurations are missing. Can I retrieve the lost configurations?

You can use the following procedure to restore the configuration:

Log on to the NetScaler command line of the primary appliance.

Run the following commands:

save config
shell
\#cp /nsconfig/ns.conf /nsconfig/ns.conf.bkup
The ns.conf.bkup file is a backup for the running configuration.

Upgrade software of both the appliances to the final release.

Log on to the NetScaler command line of the primary appliance.

Can I upgrade a NetScaler appliance directly from release 10.0 to 10.5, or should I upgrade to 10.1 first and then to 10.5?

You can directly upgrade a NetScaler appliance regardless of the version or the build number.

Can the primary appliance and secondary appliance have separate builds?

Recommended practice is to use the same version and build number on both the primary and the secondary appliance.

Can both the appliances in an High Availability (HA) pair be upgraded at the same time?

No. In an HA pair, first upgrade the secondary node and then upgrade the primary node.

Does Citrix support firmware upgrades in the amazon AWS cloud?

Can I upgrade the NetScaler instance independently of the SDX version?

It is not required to upgrade the SDX version when the NetScaler appliance is upgraded. However, some features might not work.

Can I use the FTP server to upgrade the NetScaler appliance?

No. You must first download the firmware from the Citrix download site, save it on your local computer and then upgrade the appliance.

Is the procedure for upgrading the NetScaler appliance with GSLB configurations different from an upgrade of an appliance that is not involved in GSLB?

No. The upgrade procedure is similar to the basic upgrade procedure. The only difference is that you can upgrade the standalone or HA appliances on different sites in a phased manner.

Downgrade

I have received a NetScaler appliance with the latest NetScaler release installed on it. However, I want to downgrade the software release. Can I do so?

No. If you attempt to downgrade the software release, the appliance might not work as expected, because the ns.conf file of the later release might not be compatible with the earlier release, and the appliance might restore to the factory settings.

When downgrading the NetScaler release, I followed the instructions. However, the appliance displays the following message

root@LBCOL03B# ./installns
installns version (10.0-47.7) kernel (ns-10.0-47.7.gz)
Note:
Installation may pause for up to 3 minutes while data is written to the flash.
Caution:
Do not interrupt the installation process.
Doing so may cause the system to become unusable.
Installation will proceed in 5 seconds, CTRL-C to abort
No Valid Netscaler Version Detected
root@LBCOL03B#

How is the rollback procedure performed on a NetScaler appliance?

The rollback procedure is similar to the basic upgrade procedure. Select the target build that you want to roll back to and perform the downgrade.Before rolling back to a different release, Citrix recommends that you create a copy of your current configuration files. To downgrade from a release, see Downgrading a NetScaler Standalone Appliance.

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